The present invention relates to an arrangement on a brake pedal, used for actuating the operating brakes of a motor vehicle, for releasing a lever of a shift device of a change gear. The arrangement has a first actuating member fixedly arranged in terms of movement on the pivotably mounted brake pedal and a second actuating member fixedly arranged in terms of movement on an adjusting lever mounted in the vicinity of the brake pedal. The members lock and release a locking device assigned to the lever of the shift device. A locking spring is anchored or supported on a part fixed to the vehicle and engages or is effective on the adjusting lever in one pivoting direction with the effect of a locking and an associated actuating member engages or is effective on the adjusting lever in the opposite pivoting direction with the effect of a release.
In a known arrangement of this type (U.S. Pat. No. 4,572,340), via a hydrostatic linkage connected to the hydraulics the brake pedal acts, together with the locking spring, on one lever arm of the two-armed adjusting lever. The other lever arm of the lever has corresponding recesses for the respective locking of the three positions of a bolt which is arranged rigidly on a shift lever of a shift device of a gear shiftable into a neutral position and into a further position for forward and reverse travel, so that this locking device has to be released by the brake pedal for every gear shift. The constant hydraulic coupling of the adjusting lever to the brake pedal gives rise to a disturbing influence brought about by the locking spring when relatively low finely proportioned brake forces are to be exerted.
An object of the present invention is to provide an arrangement for locking and release of a lever of a shift device, that avoids hydraulic means for locking the lever of the shift device, especially the manual selector lever of an automatic shift device, for safety reasons and to minimize or prevent undesirable influences of the locking spring during the exertion of low brake forces.
This and other objects are achieved by the present invention which provides an arrangement on a pivotably mounted brake pedal having a pivot axis and used for actuating the operating brakes of a motor vehicle, for releasing a lever of a shift device of a change gear. The arrangement comprises an adjusting lever mounted in the vicinity of the brake pedal, a locking device assigned to the lever of the shift device, a first actuating member fixedly arranged fixedly on the brake pedal, and a second actuating member arranged fixedly on the adjusting lever. The first and second actuating members lock and release the locking device assigned to the lever of the shift device. A locking spring is coupled on a part fixed to the vehicle and is operable on the adjusting lever in a first pivoting direction with the effect of a locking. One of the first or second actuating members is operable on the adjusting lever in a second, opposite pivoting direction to effect a release. The first and second actuating members are cams and are directly engageable with one another, with at least one of the first and second actuating limited pivotable range of the brake pedal including a position of rest, forces resulting on the first actuating member are at least approximately in a plane containing the pivot axis of the brake pedal.
The arrangement according to the present invention is especially suitable for those locking devices in which the lever of the shift device can be blocked in only one position, that is concerned. In the other positions a cam control of the locking device is effective on the adjusting lever, and keeps the locking spring per se under tension. The influence on the brake pedal invention, even in the narrow pivot-angle range under consideration. When the invention is used for arrangements of this type, for example according to U.S. Pat. No. 5,014,831 herein incorporated by reference, the spring coordination between the three springs employed is then carried out according to certain preferred embodiments of the present invention. For example, in one embodiment, there is a return spring coupled to the brake pedal, this return spring actuating the brake pedal in the direction of its position of rest, and the locking spring has lower spring forces than the return spring In addition, in certain embodiments, the locking device has a release spring that effects a release of the locking device, the locking spring has higher spring forces than the release spring, and the engagement surface is further shaped to cause the first and second actuating members to disengage when the brake pedal assumes its position of rest and the locking device is released.
The arrangement according to the invention is kept play-free in an advantageous way in certain embodiments by providing that the engagement surface is further shaped so that, in a limited pivot-angle range of the brake pedal adjacent to a pedal position of the brake pedal which corresponds to a released state of the locking device, the first and second actuating members are maintained in further mutual engagement, with the lever moments resulting on the brake pedal being kept low.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.